For a unit that finished 10th in the Pac-12 a year ago in pass defense, the Arizona State secondary is facing a tidal wave of pressure to perform this season.

Given that four key names are returning to lead the squad, the expectations are warranted, but also troublesome.

While the defensive line and linebacking corps work to break in their new starters, the secondary boasts a grip of veterans who have plenty of experience already. But unfortunately for ASU, a large majority of that experience is from negative results.

In 2011, the Sun Devils allowed 273 yards per game through the air in the conference, a category only Arizona and Washington were worse in.

Now with question marks across the defense, the secondary knows it will have to step up its performance for the team to attempt to hold some of the explosive Pac-12 offenses in check.

"We definitely understand that," junior cornerback Osahon Irabor said. "It's kind of our responsibility to take the defense upon ourselves and carry some of that pressure to help the new guys who haven't experienced Pac-12 football yet."

That's likely because Irabor and the rest of the ASU secondary know how cruel Pac-12 football can be.

Ahead by five points with less than two minutes remaining against UCLA last November, ASU allowed the Bruins to convert on a third-and-29 and eventually score the game-winning touchdown. Then just a week later the Sun Devil secondary turned in their worst performance in recent memory when Washington State freshman quarterback Connor Halliday tore apart ASU for 494 yards.

So even though the Sun Devils bring back the likes of Irabor, junior Alden Darby, senior Keelan Johnson and senior Deveron Carr, it doesn't mean the veteran group will automatically experience the type of results the defense needs.

A big reason why the secondary struggled last season was penalties. While former linebacker Vontaze Burfict took most of the heat for his personal fouls, the back of the ASU defense took more than their fair share of holding and pass interference flags. As a team, ASU ranked 120th, dead last, in the FBS in penalty yards per game in 2011 with 79.77.

"It's all discipline, last year, not to beat a dead horse, but we didn't have a lot of discipline," Irabor said. "This year though, that's been our focus and you're seeing a change in that. We haven't had a fight in camp and we're a team, we understand that. We're going to play smart, that's what we're focusing on."

On the positive side, the unit doesn't need to worry about adjusting to the new coaching staff terribly much. ASU Defensive Passing Game Coordinator Chris Ball coaches the secondary and much of the shells he and coach Todd Graham have implemented look the same as last season.

"It's definitely similar especially at the safety and corner positions, there's not a lot of changes really," Johnson said. "It's just terms they use and those sorts of things more than anything. I like working with Ball, he asks for our feedback and what our strengths are. He believes in me as a player, I've worked with recent players he's coached and they all say the same thing, he wants the best for me as a player and person."

Aside from the usual looks, a new wrinkle the secondary is working on is its play in the 3-3-5 stack defense. When the Sun Devils go to this they will be trying to confuse the offense by bringing different pressures in the A, B, and C gaps. The stack works well with teams who are conditioned fast to make up for a lack of size, a description ASU fits perfectly.

While the middle linebackers blitz, the cornerbacks will likely be in man coverage and the free safety, Johnson in this case, will have responsibility over the rest of the field.

The stack is where the Sun Devils' veteran leadership will particularly stand out as they will provide extra help for the newcomers working their way into the rotation.

"It's like having an extra coach, it's different when you hear something from a coach's perspective than a player's perspective," Irabor said. "When you're actually out there playing, there are some things you pick up that are actually different than what the coaches see. We're trying to hand that down to the younger guys to help them develop a bit quicker."

Some of those younger Sun Devils that will see action in the secondary this season are freshman boundary safety Ezekiel Bishop, junior spur linebacker (a hybrid linebacker-safety role) Chris Young, sophomore safety Luke Williams, and sophomore cornerback Rashad Wadood. The perceived lack of depth is concerning, but ASU players are confident the up-and-comers will be up for the challenge.

"I think we need to develop a strong core of backups for the scheme we play," Johnson said. "We need a couple other corners and safeties to come in and play for us. But I think the secondary improved a lot, the conditioning is definitely a lot harder, it keeps you guessing what we're doing and why we're doing it so we know what we're getting into and how it's preparing our bodies."

For Bishop especially, this season will be a welcomed return to football. As a true freshman a year ago, the safety tore his ACL after impressing in camp, and faced a long road to recovery. Now back in a uniform, he's glad to be playing a role.

"I'm happy to be back out there you know, a year away from football, that was hard, I'm blessed to be back and I'm not going to take anything for granted," Bishop said. "Physically I feel fine. I'm starting to get my legs under me and it's coming along good. The whole injury was the first time I ever faced adversity. It was tough but I learned the value of having patience."

For the seniors around Bishop, there won't be any time to be patient to reach their lofty goals. With the amount of star power at the quarterback position in the Pac-12, the Sun Devil secondary will have to put together a special season for ASU. But if confidence has anything to do with success, the team is in a good position to finish where it wants to.